TURBIDITY MEASUREMENTS OF NITROBENZENE IN HEXADECANE IN THE CRITICAL REGION

A series of turbidity measurements have been made for nitrobenzene in hexadecane in the critical region at various wavelengths and temperatu res. Critical amplitudes xi(0), chi(0) and B corresponding to the corr elation length, the susceptibility and the coexistence curve are relat ed through R = xi(0)[B-2/(4k(B)T(c)chi(0))](1/3), where the value of R is 0. 65 similar to 0. 67. By using this relation the turbidity data have been fitted to Ornstein-Zernike equation to obtain critical expon ents gamma and upsilon, which are consistent with the theoretical valu es within experimental uncertainties. The experimental data have also been analyzed to determine critical amplitudes when the value of gamma and upsilon are fixed at their theoretical values 1.241 and 0.63. The results have shown that xi(0) is 0.168nm(R = 0.65) and 0.174nm(R = 0. 67), and chi(0) is 2.81 x 10(-9) m(3) . J(-1)(R = 0.65) and 2.85 x 10( -9) m(3) . J(-1)(R = 0. 67), respectively.